Air-cushion vehicles

ABSTRACT

An air-cushion vehicle has inflatable means confining the cushion, preferably in the form of a skirt, acting between the ground and the vehicle undersurface.

United States Patent Cedric l-lewer Wren Whitstable, England 740,920

June 28, 1968 Jan. 5, 1971 by Curtis Dyna-Products CorporationWestfield, bid.

a corporation of Indiana Sept. 4, 1967 Great Britain Inventor Appl. No.Filed Patented Assignee Priority AIR-CUSHION VEHICLES 1 Claim, 8 DrawingFigs.

U.S. C1 180/124 Int. Cl...... B60v 1/00, B60v 1/16 180/124, 125, 119

Field of Search References Cited UNITED STATES PATENTS 3,232,266 2/1966Cockerell 180/ 124 3,246,712 4/1966 Mackie.... 180/119 3,260,322 7/1966Mackie 180/124 3,268,023 8/1966 Di Napoli, Jr. 180/124X 3,398,809 8/1968Wood et a1. 180/119 3,424,266 1/1969 Cockerell 180/124X FOREIGN PATENTS1,393,910 2/1965 France 180/124 Primary Examiner- Harry A. Levy Attorney Woodard, Weikart. Emhardt & Naughton ABSTRACT: An air-cushionvehicle has inflatable means confining the cushion, preferably in theform of a skirt, acting between the ground and the vehicle undersurface.

.PATENTED JAN Sign sum 1 [1F 4 'PATENTEU JAN 5 ISTI SHEET 2 [IF 4PATENTEUJAN Elan v 3552.519

' I snmanra l Am-cusruonvmirctss This invention relates toAir-CushionVehicles (A.C.Vs.), sometimes referred to as Ground Effect Vehicles.

In known Air-Cushion Vehicles a flow of fluid, usually air, is directedagainst a surface to produce a fluid cushion which supports a vehicle invertically spaced relationship above the said surface. Although fluidsother than air can be used, reference hereinafterwill be made solely tothe use of air. A

vehicle so supportedon an air'cushion can then be caused to movetransversely over the surface by means of a propeller, jet stream orother suitable propulsion means. When the vehicle is at rest the vehicleis supported on the base thereof, which is in contact with the surfaceabove which it is to be supported by an air cushion. When the flowof airis commenced the vehicle is lifted by reaction between the'air flow andthe surface, and/or by pressure at the underside of the 'vehicle untilan equilibrium is reached and the vehicle is supported on an aircushion. This mode of lifting is inefficient in that it requires the useof more powerful means for producing the air flow initially to raise thevehicle than are required to maintain the air cushion and to propel thevehicle.

According to the'presentinvention an comprises means for forming andmaintaining an air cushion capable of supporting the vehicle atanoperating level above a surface, means for driving the vehicle" at theoperating level over the surface and inflatable means adapted to actbetween the vehicle and the said surface, the arrangement being suchthat with the vehicle atrest, inflation of the inflatable means raisesthe vehicle so that the vertical distance that the vehicle 'has to beraised'to the operating level by the means for producing and maintainingthe air cushion is reduced.

Preferably the inflation means are adapted to be inflated by means forproducing a flow of air to produce and maintain the air cushion.

The air cushion may be at least partially surrounded by a dependent rimor skirt which is flexible or movable to enable the vehicle to move overuneven terrain. In accordance with an important feature of the presentinvention the dependent rim or skirt is constituted by the inflatablemeans. Thus an annular closed inflatable skirt may surround theundersurface of the vehicle.

Further features of the invention will become apparent from thedescription of a particular embodiment thereof made with reference tothe accompanying drawings wherein:

FIG. 1 is a side view of an Air-Cushion Vehicle in accordance with theparticular embodiment;

FIG. 2 is a plan view of the Vehicle;

FIG. 3 is an underneath plan view of the-Vehicle;

FIG. 4 is a section on the line IV-IV of FIG. 2; and

FIGS. 5, 6, 7 and 8 are front views, partly in section, show ing thevehicle raising itself onto its air cushion.

Referring now particularly to FIGS. 1, 2 and 3 of the drawings, theAir-Cushion Vehicle shown therein comprises a body or hull 1 which isgenerally rectangular viewed in plan having pointed bows 2. Acompartment 3 in which the driver of the vehicle and one passenger cansit side-by-side has a divided windscreen 4 and side. windows 5. Asliding roof over the compartment 3 provides access for the driver andpassenger. Immediately behind the compartment 3 is the upper casing orfunnel 6 of a vertically extending shaft 7 through which air is impelleddownwardly to form an air cushion which supports the vehicle. As can beseen in FIG. 2 of the drawings the funnel is hemielliptical viewed inplan, the curved end of the funnel being rearwardly directed. The partof the shaft 7 within the funnel is of circular cross section. Atwo-stroke twin cylinder air cooled petrol engine 8 driving a 13 bladedimpeller fan 9 is positioned in theupper part of the shaft 7 adjacentthe base of the funnel 6. The fan 9 is positioned above the motor and isof the axial type adapted to draw air vertically downwards into theshaft. As can be seen in FIG. 3 of the drawings the shaft 7 below thefunnel 6 is of square cross section and is defined between front, rearand sidewalls 10, 11, 12 and 13. Transversely extending struts l4 securethe engine 8 Air-Cushion Vehicle to the sidewalls 12 and13. Watertightflat bottom elements I5 and 16 close the underside of the vehicle infront of and behind the shaft 7. Dependent elements 21 on which thevehicle can skid, in the event that the skirt deflates, are provided onthe undersurface of the elements 15 and 16: The Air-Cushion forsupporting the vehicle is formed in the lower end part of shaft 7.

A pair of elongate chambers 17 extend, one on either side of thevehicle, from the stern thereof to positions immediately behind the bow(see FIG. 1). As can well be seen in FIG. 4 of the drawings, eachchamber 17 has an inner vertically extending sidewall formed by asidewall 12 or 13 of the shaft 7, a horizontal bottom wall 18 level withbottom elements 15 and I6 and an outer convex sidewall 19 ofsemicircular cross section. A bore 20 is formed through each shaftsidewall to allow air drawn into the shaft by the fan 9 to flow into thechambers 17. An elongate duct 22 of rectangular cross section extendsfrom each bore 20 to a position immediately below the fan 9. The ducts22 may include unidirectional valves which allow the passage of air fromthe shaft 7 to the chambers 17 but pipe 24 is positioned centrally ofthe length of chamber. The

pipes 24 allow air in the chambers 17 to pass into the inflatable skirtto be described hereinafter.

A dependent flexible skirting strip 26 of air retaining material, forexample canvas, of greater width than the bottom wall 18 of the chamber17, links the radially inner and outer margins of the chamber 17. Thestrip also depends from positions at the front and rear of the vehiclewhich are spaced apart by the width of the wall 18 so that a continuousannular inflatable skirt of closed tubular form surrounds theundersurface of the vehicle (see FIG. 3). When inflated (see for exampleFIG. 4), the skirt 26 is of semicircular cross section. Thecross-sectional area of the chamber 17 is greater than that of theinflated skirt 26.

A two-stroke twin cylinder air cooled petrol engine 27 similar to theengine 8 is mounted on upstanding stays 28 at the rear of the vehiclebehind the funnel 6 and is surrounded by aprotective cowl 29 of wiremesh. The engine 27 drives a two blade axial fan 30 which directs astream of air rearwardly with respect to the vehicle. A rudder in theform of a tail fin 31 pivotal about a vertical axis, is positionedbehind the fan 30 and is controlled by cables 32 generally indicated indotted lines which are connected to a steering rod 33 in the compartment3 (see FIG. 2). A hoop 34 which protects the fin 31 extends rearwardlyfrom the stern of the vehicle.

The operation of the vehicle will now be described with reference toFIGS. 5 to 8 of the drawings. The arrows indicate the direction of airflow. The vehicle is shown resting on a supporting surface 35 in FIG. 5of the drawings. It will be noted that the undersurface of the skids 21abut the surface 35. The fan 9 driven by the engine 8 commences to drawair into the shaft 7 and air pressure in the shaft rises as the lowerend thereof is closed by the supporting surface and the skirt 26. Airenters the chambers 17 through ducts 22 and bores 20, and the skirt 26from the chambers 17 through pipes 24. Inflation of the skirt proceedsas is shown in FIGS. 6 and 7 of the drawings and the vehicle is liftedby the air in the skirt expanding the skirt to the inflated semicircularform. In the fully inflated condition of the skirt 26 shown in FIG. 7the vehicle is raised to a vertical level immediately below theoperating level. Formation of the supporting air cushion then raises thevehicle to the operating level shown in FIG. 8. The vehicle supported onits air cushion hovers above the supporting surface 35 in verticallyspaced relationship thereto and may be driven by the impelling motor 27and controlled by movement of the tail fin 3]. In use the rigid chambers17 serve as plenums for the skin 26 and the skirt even if perforated ortorn to a substantial amount, is maintained in inflation by thereservoir of air under pressure in the chambers 17. The vehicledescribed is capable of moving over land, water or a mixed terrain.

lclaim:

1. An air-cushion vehicle comprising a vertically extending shaft, meansfor impelling air down said shaft to produce an air-cushion capable ofsupporting the vehicle at an operating level above a surface, means fordriving the vehicle at said level over said surface, a rigid chamberextending along each side of the vehicle, means for communicating theinteriors of the chambers with the interior of the shaft, an annularinflatable skirt having a cross section of a closed loop surrounding themarginal part of 'the undersurface of the vehicle, and meanscommunicating the interior of the skirt with the interiors of thechambers, said skirt and said undersurface of said vehicle forming acavity over said surface for receiving air directly from said shaft forproduction of said air-cushion, said skirt being inflated by the meansfor producing the flow of air to form and maintain the air-cushion, thearrangement being such that with the vehicle at rest, inflation of saidskirt raises the vehicle so that the vertical distance that the vehiclehas to be raised to said level by the means for forming and maintainingthe air-cushion is reduced, each chamber has a horizontal floor, whereinthe undersurface of said floor forms the upper wall of the inflatedskirt and wherein said means communicating the interior of the skirtwith the interiors of the chambers comprises, for each chamber a pipeextending upwardly from a through bore in said floor, the upper end ofsaid pipe being disposed above the position at which the meanscommunicating the interior of said chamber with the interior of saidshaft enters said chamber.

1. An air-cushion vehicle comprising a vertically extending shaft, meansfor impelling air down said shaft to produce an aircushion capable ofsupporting the vehicle at an operating level above a surface, means fordriving the vehicle at said level over said surface, a rigid chamberextending along each side of the vehicle, means for communicating theinteriors of the chambers with the interior of the shaft, an annularinflatable skirt having a cross section of a closed loop surrounding themarginal part of the undersurface of the vehicle, and meanscommunicating the interior of the skirt with the interiors of thechambers, said skirt and said undersurface of said vehicle forming acavity over said surface for receiving air directly from said shaft forproduction of said air-cushion, said skirt being inflated by the meansfor producing the flow of air to form and maintain the aircushion, thearrangement being such that with the vehicle at rest, inflation of saidskirt raises the vehicle so that the vertical distance that the vehiclehas to be raised to said level by the means for forming and maintainingthe air-cushion is reduced, each chamber has a horizontal floor, whereinthe undersurface of said floor forms the upper wall of the inflatedskirt and wherein said means communicating the interior of the skirtwith the interiors of the chambers comprises, for each chamber a pipeextending upwardly from a through bore in said floor, the upper end ofsaid pipe being disposed above the position at which the meanscommunicating the interior of said chamber with the interior of saidshaft enters said chamber.